Petrotrichis, Darby, Michael, 2015

Darby, Michael, 2015, Studies of Bolivian Ptiliidae (Coleoptera) 2: The subfamily Acrotrichinae including two new genera Petrotrichis and Microtrichis, and eight new species of Acrotrichis, Zootaxa 3999 (2), pp. 190-210 : 204

Petrotrichis gen.n. ( Acrotrichinae , Acrotrichini)

( Figs 10 A–O)

Description. Body elongate, rather broad, convex; without clear microsculpture, appearing polished and shining, pubescent. Head moderately broad, eyes present, antennae 11 segmented with small groups of sensillae on antennomeres 10,11. Male protibiae flattened, with a dense mass of short setae. Pronotum broader than long, sides rounded in posterior third, slightly wider than the elytra, with a small tooth at the hind angle, lateral margins bordered. Elytra +/- quadrate, subtruncate apically, exposing +/- 4 abdominal segments. Scutellum triangular. Wings of usual ptiliid type. Proventrum very narrow in front of procoxae which are contiguous and open behind. Mesoventrum short, collar biconvex medially and barely sloping to side margins, hind margins straight laterad of mesocoxae, sloping anteriorly to margins, mesocoxae contiguous separated anteriorly by a narrow keel which does not reach the collar. Metaventrum hind margin straight, toothed mesad of coxae, metacoxae with rounded plates which stop short of the lateral margins, separated by approximately one third of the metaventral width. Pygidium barely bidentate, anterior border without setae. Male ventrite 7 with wide incision and pairs of strongly developed horn-like setae at sides. Spermatheca with poorly developed wide duct. Aedeagus with two blunt projections.

The new genus is named after the collector Petr Baňař; gender neuter. Type species: P. rotundata sp. n.

Separation from related species. Most closely related to Chirostirca with its single species gomyi (no male known) ( Fig. 10 B) described by Johnson (1985) from Mauritius, and similar to that species in its shining and globose appearance, the shape of the meso- and mentaventra, the wide separation of the metacoxae, and the form of the pygidium, but differing in the possession of much shorter antennae, strongly rounded pronotal margins which are not sinuate before the hind angles, and are not pointed or rearwards projecting, the lack of strong sculpturation on the metaventrum and elytra, and the mentum which is longer and more tapering.

From Acrotrichis Petrotrichis may be distinguished by its more globular shape, the polished appearance of the pronotum and elytra both of which lack visible sculpturation and the form of the pronotal hind angles which barely extend rearwards and possess a small tooth.

Figures

FIGURE 10. Chirostirca gomyi Johnson: B, habitus (paratype in the MMC). Petrotrichis rotundata: A, habitus; C, antennomeres 3 – 11; D, mentum and submentum x 1400 D, side of pronotum viewed at 45 °; E, spermatheca; F, aedeagus; G, male ventrite seven; H, underside showing meso and metaventra; I, pygidium; J, male front tibia x 1520; K, male ventrite six x 1240; L, scutellum and metascutellum; M, elytra showing lack of visible cell structure x 1880; N, antennomeres 10 & 11 showing groups of sensillae x 2060; O, pronotal hind angles showing small tooth x 1820.